Tubular explosive transmission line



April 1962 A. J. GRANDY ETAL 3,027,839

TUBULAR EXPLOSIVEI TRANSMISSION LINE Filed April 2, 1959 H Wee l0 l3FIG.2

I k l8 '7 22 23 2| FIG.3.

INVENTORJ, ANDREW J. GRANDY By ROBERT S. SHULMAN ATTORNEYS:

United States Patent TUBULAR EXPLOSIVE TRANSMISSION LINE Andrew J.Grandy, North Hills, and Robert S. Shnlman,

Philadelphia, Pa., assignors to the United States of America asrepresented by the Secretary of the Army Filed Apr. 2, 1959, Ser. No.803,808 2 Claims. (Cl. 102-27) (Granted under Title 35, US. Code (1952),see. 266) The invention described herein may be manufactured and used byor for the Government for governmental purposes without the payment tous of any royalty thereon.

This invention relates to explosive transmission lines which are ignitedat one location to generate a gas usable at another location to producean elfect such as the ignition of a propellant or the like.

In the use of the currently available explosive transmission lines,difficulty is encountered due to pop-out" or rupture of the lines outerwall. In accordance with the present invention, this dilfrculty isavoided by the provision of an improved explosive transmission linewhich is hollow at its center and has its ignition powder in the form ofa tube located between a relatively strong outer tube and a relativelyweak inner tube. With this structure, the stress to which the outer wallis subjected is somewhat reduced by the layer of powder between the twolayers and is further reduced by the collapse of the inner tube whichprovides greater space for the generated gases.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawings and itsscope is indicated by the appended claims.

Referring to the drawings:

FIG. 1 is a longitudinal sectional view of the improved transmissionline,

FIG. 2 is an enlarged section of the line, and

FIG. 3 indicates how the line is utilized to fire a recoilless riflewhich is hand carried and fired from the shoulder.

As indicated by FIGS. 1 and 2, the line includes a relatively strongouter tube and a relatively weak inner tube 11. Between these tubes is alayer 12 of black powder. The outer tube sheath 13 of nylon, glass braidor the like.

The tubes 10 and 11 may consist of a synthetic material such aspolyethylene or the equivalent. Suitable 10 may be surrounded by a3,027,839 Patented Apr. 3, 1962 thickness for the walls of the tubes are0.030 in. for the outer tube and 0.020 in. for the inner tube.

To one end of the line is fixed an adapter 14 which has a thread 15 andis hollowed out to provide an igniter powder chamber 16. A collet 17enclosing a primer 18 is at the other end of the line.

The improved explosive transmission line is utilized to fire arecoilless rifle as indicated by FIG. 3. From this figure it can be seenthat the adapter 14 is threaded into the base of a cartridge 19 which ischambered in a rifie 20. The firing mechanism 21 of this rifle has acasing which is provided at its breech end with flange 22 formed to bereceived in the collet 17 for maintaining the primer 18 in operativerelation with a firing pin 23. Since the firing mechanism forms no partof the present invention it is not described in detail.

In the operation of the above-described line, the firing of the primer18 ignites the black powder 12 and burning of this powder fires theigniter 16, the burning of which ignites the propellant of thecartridge.

As can be readily understood by those skilled in the art, the hereindisclosed explosive transmission line has the advantage that it isrelatively easy to manufacture, is hermetically sealed from one end tothe other and has a pressure resistance which makes suitable for use inclose proximity to personnel.

We claim:

1. An explosive transmission line including an outer tube, an inner tubeprovided with a hollow axial space, and a tubular layer of black powderbetween said tubes, the outer tube being of thicker and strongermaterial than the inner tube and in addition is provided with areinforcing sheath whereby only said inner tube is ruptured by the forcegenerated by the burning of said powder.

2. An explosive transmission line according to claim 1 wherein adetonator is fixed to one end of said line for firing said powder and amember having an igniter chamber opening into said inner tube is fixedto the other end of said line.

References Cited in the file of this patent UNITED STATES PATENTS

